package agent import ( "context" "crypto/sha512" "crypto/tls" "encoding/json" "errors" "fmt" "io" "io/ioutil" "log" "net" "net/http" "os" "path/filepath" "regexp" "strconv" "strings" "sync" "time" "github.com/hashicorp/consul/agent/consul" "github.com/hashicorp/consul/agent/consul/structs" "github.com/hashicorp/consul/agent/systemd" "github.com/hashicorp/consul/api" "github.com/hashicorp/consul/ipaddr" "github.com/hashicorp/consul/lib" "github.com/hashicorp/consul/logger" "github.com/hashicorp/consul/types" "github.com/hashicorp/consul/watch" "github.com/hashicorp/go-sockaddr/template" "github.com/hashicorp/go-uuid" "github.com/hashicorp/raft" "github.com/hashicorp/serf/coordinate" "github.com/hashicorp/serf/serf" "github.com/shirou/gopsutil/host" ) const ( // Path to save agent service definitions servicesDir = "services" // Path to save local agent checks checksDir = "checks" checkStateDir = "checks/state" // Default reasons for node/service maintenance mode defaultNodeMaintReason = "Maintenance mode is enabled for this node, " + "but no reason was provided. This is a default message." defaultServiceMaintReason = "Maintenance mode is enabled for this " + "service, but no reason was provided. This is a default message." ) // dnsNameRe checks if a name or tag is dns-compatible. var dnsNameRe = regexp.MustCompile(`^[a-zA-Z0-9\-]+$`) // delegate defines the interface shared by both // consul.Client and consul.Server. type delegate interface { Encrypted() bool GetLANCoordinate() (*coordinate.Coordinate, error) Leave() error LANMembers() []serf.Member LocalMember() serf.Member JoinLAN(addrs []string) (n int, err error) RemoveFailedNode(node string) error RPC(method string, args interface{}, reply interface{}) error SnapshotRPC(args *structs.SnapshotRequest, in io.Reader, out io.Writer, replyFn structs.SnapshotReplyFn) error Shutdown() error Stats() map[string]map[string]string } // notifier is called after a successful JoinLAN. type notifier interface { Notify(string) error } // The agent is the long running process that is run on every machine. // It exposes an RPC interface that is used by the CLI to control the // agent. The agent runs the query interfaces like HTTP, DNS, and RPC. // However, it can run in either a client, or server mode. In server // mode, it runs a full Consul server. In client-only mode, it only forwards // requests to other Consul servers. type Agent struct { // config is the agent configuration. config *Config // Used for writing our logs logger *log.Logger // Output sink for logs LogOutput io.Writer // Used for streaming logs to LogWriter *logger.LogWriter // delegate is either a *consul.Server or *consul.Client // depending on the configuration delegate delegate // acls is an object that helps manage local ACL enforcement. acls *aclManager // state stores a local representation of the node, // services and checks. Used for anti-entropy. state *localState // checkReapAfter maps the check ID to a timeout after which we should // reap its associated service checkReapAfter map[types.CheckID]time.Duration // checkMonitors maps the check ID to an associated monitor checkMonitors map[types.CheckID]*CheckMonitor // checkHTTPs maps the check ID to an associated HTTP check checkHTTPs map[types.CheckID]*CheckHTTP // checkTCPs maps the check ID to an associated TCP check checkTCPs map[types.CheckID]*CheckTCP // checkTTLs maps the check ID to an associated check TTL checkTTLs map[types.CheckID]*CheckTTL // checkDockers maps the check ID to an associated Docker Exec based check checkDockers map[types.CheckID]*CheckDocker // checkLock protects updates to the check* maps checkLock sync.Mutex // dockerClient is the client for performing docker health checks. dockerClient *DockerClient // eventCh is used to receive user events eventCh chan serf.UserEvent // eventBuf stores the most recent events in a ring buffer // using eventIndex as the next index to insert into. This // is guarded by eventLock. When an insert happens, the // eventNotify group is notified. eventBuf []*UserEvent eventIndex int eventLock sync.RWMutex eventNotify NotifyGroup reloadCh chan chan error shutdown bool shutdownCh chan struct{} shutdownLock sync.Mutex // joinLANNotifier is called after a successful JoinLAN. joinLANNotifier notifier // retryJoinCh transports errors from the retry join // attempts. retryJoinCh chan error // endpoints maps unique RPC endpoint names to common ones // to allow overriding of RPC handlers since the golang // net/rpc server does not allow this. endpoints map[string]string endpointsLock sync.RWMutex // dnsAddr is the address the DNS server binds to dnsAddrs []ProtoAddr // dnsServer provides the DNS API dnsServers []*DNSServer // httpAddrs are the addresses per protocol the HTTP server binds to httpAddrs []ProtoAddr // httpServers provides the HTTP API on various endpoints httpServers []*HTTPServer // wgServers is the wait group for all HTTP and DNS servers wgServers sync.WaitGroup // watchPlans tracks all the currently-running watch plans for the // agent. watchPlans []*watch.Plan } func New(c *Config) (*Agent, error) { if c.Datacenter == "" { return nil, fmt.Errorf("Must configure a Datacenter") } if c.DataDir == "" && !c.DevMode { return nil, fmt.Errorf("Must configure a DataDir") } dnsAddrs, err := c.DNSAddrs() if err != nil { return nil, fmt.Errorf("Invalid DNS bind address: %s", err) } httpAddrs, err := c.HTTPAddrs() if err != nil { return nil, fmt.Errorf("Invalid HTTP bind address: %s", err) } acls, err := newACLManager(c) if err != nil { return nil, err } a := &Agent{ config: c, acls: acls, checkReapAfter: make(map[types.CheckID]time.Duration), checkMonitors: make(map[types.CheckID]*CheckMonitor), checkTTLs: make(map[types.CheckID]*CheckTTL), checkHTTPs: make(map[types.CheckID]*CheckHTTP), checkTCPs: make(map[types.CheckID]*CheckTCP), checkDockers: make(map[types.CheckID]*CheckDocker), eventCh: make(chan serf.UserEvent, 1024), eventBuf: make([]*UserEvent, 256), joinLANNotifier: &systemd.Notifier{}, reloadCh: make(chan chan error), retryJoinCh: make(chan error), shutdownCh: make(chan struct{}), endpoints: make(map[string]string), dnsAddrs: dnsAddrs, httpAddrs: httpAddrs, } if err := a.resolveTmplAddrs(); err != nil { return nil, err } // Try to get an advertise address switch { case a.config.AdvertiseAddr != "": ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddr) if err != nil { return nil, fmt.Errorf("Advertise address resolution failed: %v", err) } if net.ParseIP(ipStr) == nil { return nil, fmt.Errorf("Failed to parse advertise address: %v", ipStr) } a.config.AdvertiseAddr = ipStr case a.config.BindAddr != "" && !ipaddr.IsAny(a.config.BindAddr): a.config.AdvertiseAddr = a.config.BindAddr default: ip, err := consul.GetPrivateIP() if ipaddr.IsAnyV6(a.config.BindAddr) { ip, err = consul.GetPublicIPv6() } if err != nil { return nil, fmt.Errorf("Failed to get advertise address: %v", err) } a.config.AdvertiseAddr = ip.String() } // Try to get an advertise address for the wan if a.config.AdvertiseAddrWan != "" { ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddrWan) if err != nil { return nil, fmt.Errorf("Advertise WAN address resolution failed: %v", err) } if net.ParseIP(ipStr) == nil { return nil, fmt.Errorf("Failed to parse advertise address for WAN: %v", ipStr) } a.config.AdvertiseAddrWan = ipStr } else { a.config.AdvertiseAddrWan = a.config.AdvertiseAddr } // Create the default set of tagged addresses. a.config.TaggedAddresses = map[string]string{ "lan": a.config.AdvertiseAddr, "wan": a.config.AdvertiseAddrWan, } return a, nil } func (a *Agent) Start() error { c := a.config logOutput := a.LogOutput if a.logger == nil { if logOutput == nil { logOutput = os.Stderr } a.logger = log.New(logOutput, "", log.LstdFlags) } // Retrieve or generate the node ID before setting up the rest of the // agent, which depends on it. if err := a.setupNodeID(c); err != nil { return fmt.Errorf("Failed to setup node ID: %v", err) } // create the local state a.state = NewLocalState(c, a.logger) // create the config for the rpc server/client consulCfg, err := a.consulConfig() if err != nil { return err } // link consul client/server with the state consulCfg.ServerUp = a.state.ConsulServerUp // Setup either the client or the server. if c.Server { server, err := consul.NewServerLogger(consulCfg, a.logger) if err != nil { return fmt.Errorf("Failed to start Consul server: %v", err) } a.delegate = server a.state.delegate = server } else { client, err := consul.NewClientLogger(consulCfg, a.logger) if err != nil { return fmt.Errorf("Failed to start Consul client: %v", err) } a.delegate = client a.state.delegate = client } // Load checks/services/metadata. if err := a.loadServices(c); err != nil { return err } if err := a.loadChecks(c); err != nil { return err } if err := a.loadMetadata(c); err != nil { return err } // Start watching for critical services to deregister, based on their // checks. go a.reapServices() // Start handling events. go a.handleEvents() // Start sending network coordinate to the server. if !c.DisableCoordinates { go a.sendCoordinate() } // Write out the PID file if necessary. if err := a.storePid(); err != nil { return err } // start DNS servers if err := a.listenAndServeDNS(); err != nil { return err } // create listeners and unstarted servers // see comment on listenHTTP why we are doing this httpln, err := a.listenHTTP(a.httpAddrs) if err != nil { return err } // start HTTP servers for _, l := range httpln { srv := NewHTTPServer(l.Addr().String(), a) if err := a.serveHTTP(l, srv); err != nil { return err } a.httpServers = append(a.httpServers, srv) } // register watches if err := a.reloadWatches(a.config); err != nil { return err } // start retry join go a.retryJoin() go a.retryJoinWan() return nil } func (a *Agent) listenAndServeDNS() error { notif := make(chan ProtoAddr, len(a.dnsAddrs)) for _, p := range a.dnsAddrs { p := p // capture loop var // create server s, err := NewDNSServer(a) if err != nil { return err } a.dnsServers = append(a.dnsServers, s) // start server a.wgServers.Add(1) go func() { defer a.wgServers.Done() err := s.ListenAndServe(p.Net, p.Addr, func() { notif <- p }) if err != nil && !strings.Contains(err.Error(), "accept") { a.logger.Printf("[ERR] agent: Error starting DNS server %s (%s): %v", p.Addr, p.Net, err) } }() } // wait for servers to be up timeout := time.After(time.Second) for range a.dnsAddrs { select { case p := <-notif: a.logger.Printf("[INFO] agent: Started DNS server %s (%s)", p.Addr, p.Net) continue case <-timeout: return fmt.Errorf("agent: timeout starting DNS servers") } } return nil } // listenHTTP binds listeners to the provided addresses and also returns // pre-configured HTTP servers which are not yet started. The motivation is // that in the current startup/shutdown setup we de-couple the listener // creation from the server startup assuming that if any of the listeners // cannot be bound we fail immediately and later failures do not occur. // Therefore, starting a server with a running listener is assumed to not // produce an error. // // The second motivation is that an HTTPS server needs to use the same TLSConfig // on both the listener and the HTTP server. When listeners and servers are // created at different times this becomes difficult to handle without keeping // the TLS configuration somewhere or recreating it. // // This approach should ultimately be refactored to the point where we just // start the server and any error should trigger a proper shutdown of the agent. func (a *Agent) listenHTTP(addrs []ProtoAddr) ([]net.Listener, error) { var ln []net.Listener for _, p := range addrs { var l net.Listener var err error switch { case p.Net == "unix": l, err = a.listenSocket(p.Addr, a.config.UnixSockets) case p.Net == "tcp" && p.Proto == "http": l, err = net.Listen("tcp", p.Addr) case p.Net == "tcp" && p.Proto == "https": var tlscfg *tls.Config tlscfg, err = a.config.IncomingHTTPSConfig() if err != nil { break } l, err = tls.Listen("tcp", p.Addr, tlscfg) default: return nil, fmt.Errorf("%s:%s listener not supported", p.Net, p.Proto) } if err != nil { for _, l := range ln { l.Close() } return nil, err } if tcpl, ok := l.(*net.TCPListener); ok { l = &tcpKeepAliveListener{tcpl} } ln = append(ln, l) } return ln, nil } // tcpKeepAliveListener sets TCP keep-alive timeouts on accepted // connections. It's used by NewHttpServer so dead TCP connections // eventually go away. type tcpKeepAliveListener struct { *net.TCPListener } func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) { tc, err := ln.AcceptTCP() if err != nil { return } tc.SetKeepAlive(true) tc.SetKeepAlivePeriod(30 * time.Second) return tc, nil } func (a *Agent) listenSocket(path string, perm FilePermissions) (net.Listener, error) { if _, err := os.Stat(path); !os.IsNotExist(err) { a.logger.Printf("[WARN] agent: Replacing socket %q", path) } if err := os.Remove(path); err != nil && !os.IsNotExist(err) { return nil, fmt.Errorf("error removing socket file: %s", err) } l, err := net.Listen("unix", path) if err != nil { return nil, err } if err := setFilePermissions(path, perm); err != nil { return nil, fmt.Errorf("Failed setting up HTTP socket: %s", err) } return l, nil } func (a *Agent) serveHTTP(l net.Listener, srv *HTTPServer) error { // https://github.com/golang/go/issues/20239 // // In go.8.1 there is a race between Serve and Shutdown. If // Shutdown is called before the Serve go routine was scheduled then // the Serve go routine never returns. This deadlocks the agent // shutdown for some tests since it will wait forever. // // Since we need to check for an unexported type (*tls.listener) // we cannot just perform a type check since the compiler won't let // us. We might be able to use reflection but the fmt.Sprintf() hack // works just as well. srv.proto = "http" if strings.Contains("*tls.listener", fmt.Sprintf("%T", l)) { srv.proto = "https" } notif := make(chan string) a.wgServers.Add(1) go func() { defer a.wgServers.Done() notif <- srv.Addr err := srv.Serve(l) if err != nil && err != http.ErrServerClosed { a.logger.Print(err) } }() select { case addr := <-notif: if srv.proto == "https" { a.logger.Printf("[INFO] agent: Started HTTPS server on %s", addr) } else { a.logger.Printf("[INFO] agent: Started HTTP server on %s", addr) } return nil case <-time.After(time.Second): return fmt.Errorf("agent: timeout starting HTTP servers") } } // reloadWatches stops any existing watch plans and attempts to load the given // set of watches. func (a *Agent) reloadWatches(cfg *Config) error { // Watches use the API to talk to this agent, so that must be enabled. addrs, err := cfg.HTTPAddrs() if err != nil { return err } if len(addrs) == 0 { return fmt.Errorf("watch plans require an HTTP or HTTPS endpoint") } // Stop the current watches. for _, wp := range a.watchPlans { wp.Stop() } a.watchPlans = nil // Fire off a goroutine for each new watch plan. for _, wp := range cfg.WatchPlans { a.watchPlans = append(a.watchPlans, wp) go func(wp *watch.Plan) { wp.Handler = makeWatchHandler(a.LogOutput, wp.Exempt["handler"]) wp.LogOutput = a.LogOutput addr := addrs[0].String() if addrs[0].Net == "unix" { addr = "unix://" + addr } if err := wp.Run(addr); err != nil { a.logger.Printf("[ERR] Failed to run watch: %v", err) } }(wp) } return nil } // consulConfig is used to return a consul configuration func (a *Agent) consulConfig() (*consul.Config, error) { // Start with the provided config or default config base := consul.DefaultConfig() // a.config.ConsulConfig, if set, is a partial configuration for the // consul server or client. Therefore, clone and augment it but // don't use it as base directly. if a.config.ConsulConfig != nil { base = new(consul.Config) *base = *a.config.ConsulConfig } // This is set when the agent starts up base.NodeID = a.config.NodeID // Apply dev mode base.DevMode = a.config.DevMode // Apply performance factors if a.config.Performance.RaftMultiplier > 0 { base.ScaleRaft(a.config.Performance.RaftMultiplier) } // Override with our config if a.config.Datacenter != "" { base.Datacenter = a.config.Datacenter } if a.config.DataDir != "" { base.DataDir = a.config.DataDir } if a.config.NodeName != "" { base.NodeName = a.config.NodeName } if a.config.Ports.SerfLan != 0 { base.SerfLANConfig.MemberlistConfig.BindPort = a.config.Ports.SerfLan base.SerfLANConfig.MemberlistConfig.AdvertisePort = a.config.Ports.SerfLan } if a.config.Ports.SerfWan != 0 { base.SerfWANConfig.MemberlistConfig.BindPort = a.config.Ports.SerfWan base.SerfWANConfig.MemberlistConfig.AdvertisePort = a.config.Ports.SerfWan } if a.config.BindAddr != "" { bindAddr := &net.TCPAddr{ IP: net.ParseIP(a.config.BindAddr), Port: a.config.Ports.Server, } base.RPCAddr = bindAddr // Set the Serf configs using the old default behavior, we may // override these in the code right below. base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.BindAddr base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.BindAddr } if a.config.SerfLanBindAddr != "" { base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.SerfLanBindAddr } if a.config.SerfWanBindAddr != "" { base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.SerfWanBindAddr } if a.config.AdvertiseAddr != "" { base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr if a.config.AdvertiseAddrWan != "" { base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrWan } base.RPCAdvertise = &net.TCPAddr{ IP: net.ParseIP(a.config.AdvertiseAddr), Port: a.config.Ports.Server, } } if a.config.AdvertiseAddrs.SerfLan != nil { base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrs.SerfLan.IP.String() base.SerfLANConfig.MemberlistConfig.AdvertisePort = a.config.AdvertiseAddrs.SerfLan.Port } if a.config.AdvertiseAddrs.SerfWan != nil { base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrs.SerfWan.IP.String() base.SerfWANConfig.MemberlistConfig.AdvertisePort = a.config.AdvertiseAddrs.SerfWan.Port } if a.config.ReconnectTimeoutLan != 0 { base.SerfLANConfig.ReconnectTimeout = a.config.ReconnectTimeoutLan } if a.config.ReconnectTimeoutWan != 0 { base.SerfWANConfig.ReconnectTimeout = a.config.ReconnectTimeoutWan } if a.config.EncryptVerifyIncoming != nil { base.SerfWANConfig.MemberlistConfig.GossipVerifyIncoming = *a.config.EncryptVerifyIncoming base.SerfLANConfig.MemberlistConfig.GossipVerifyIncoming = *a.config.EncryptVerifyIncoming } if a.config.EncryptVerifyOutgoing != nil { base.SerfWANConfig.MemberlistConfig.GossipVerifyOutgoing = *a.config.EncryptVerifyOutgoing base.SerfLANConfig.MemberlistConfig.GossipVerifyOutgoing = *a.config.EncryptVerifyOutgoing } if a.config.AdvertiseAddrs.RPC != nil { base.RPCAdvertise = a.config.AdvertiseAddrs.RPC } if a.config.Bootstrap { base.Bootstrap = true } if a.config.RejoinAfterLeave { base.RejoinAfterLeave = true } if a.config.BootstrapExpect != 0 { base.BootstrapExpect = a.config.BootstrapExpect } if a.config.Protocol > 0 { base.ProtocolVersion = uint8(a.config.Protocol) } if a.config.RaftProtocol != 0 { base.RaftConfig.ProtocolVersion = raft.ProtocolVersion(a.config.RaftProtocol) } if a.config.ACLToken != "" { base.ACLToken = a.config.ACLToken } if a.config.ACLAgentToken != "" { base.ACLAgentToken = a.config.ACLAgentToken } if a.config.ACLMasterToken != "" { base.ACLMasterToken = a.config.ACLMasterToken } if a.config.ACLDatacenter != "" { base.ACLDatacenter = a.config.ACLDatacenter } if a.config.ACLTTLRaw != "" { base.ACLTTL = a.config.ACLTTL } if a.config.ACLDefaultPolicy != "" { base.ACLDefaultPolicy = a.config.ACLDefaultPolicy } if a.config.ACLDownPolicy != "" { base.ACLDownPolicy = a.config.ACLDownPolicy } if a.config.ACLReplicationToken != "" { base.ACLReplicationToken = a.config.ACLReplicationToken } if a.config.ACLEnforceVersion8 != nil { base.ACLEnforceVersion8 = *a.config.ACLEnforceVersion8 } if a.config.SessionTTLMinRaw != "" { base.SessionTTLMin = a.config.SessionTTLMin } if a.config.Autopilot.CleanupDeadServers != nil { base.AutopilotConfig.CleanupDeadServers = *a.config.Autopilot.CleanupDeadServers } if a.config.Autopilot.LastContactThreshold != nil { base.AutopilotConfig.LastContactThreshold = *a.config.Autopilot.LastContactThreshold } if a.config.Autopilot.MaxTrailingLogs != nil { base.AutopilotConfig.MaxTrailingLogs = *a.config.Autopilot.MaxTrailingLogs } if a.config.Autopilot.ServerStabilizationTime != nil { base.AutopilotConfig.ServerStabilizationTime = *a.config.Autopilot.ServerStabilizationTime } if a.config.NonVotingServer { base.NonVoter = a.config.NonVotingServer } if a.config.Autopilot.RedundancyZoneTag != "" { base.AutopilotConfig.RedundancyZoneTag = a.config.Autopilot.RedundancyZoneTag } if a.config.Autopilot.DisableUpgradeMigration != nil { base.AutopilotConfig.DisableUpgradeMigration = *a.config.Autopilot.DisableUpgradeMigration } if a.config.Autopilot.UpgradeVersionTag != "" { base.AutopilotConfig.UpgradeVersionTag = a.config.Autopilot.UpgradeVersionTag } // make sure the advertise address is always set if base.RPCAdvertise == nil { base.RPCAdvertise = base.RPCAddr } // set the src address for outgoing rpc connections // Use port 0 so that outgoing connections use a random port. if !ipaddr.IsAny(base.RPCAddr.IP) { base.RPCSrcAddr = &net.TCPAddr{IP: base.RPCAddr.IP} } // Format the build string revision := a.config.Revision if len(revision) > 8 { revision = revision[:8] } base.Build = fmt.Sprintf("%s%s:%s", a.config.Version, a.config.VersionPrerelease, revision) // Copy the TLS configuration base.VerifyIncoming = a.config.VerifyIncoming || a.config.VerifyIncomingRPC if a.config.CAPath != "" || a.config.CAFile != "" { base.UseTLS = true } base.VerifyOutgoing = a.config.VerifyOutgoing base.VerifyServerHostname = a.config.VerifyServerHostname base.CAFile = a.config.CAFile base.CAPath = a.config.CAPath base.CertFile = a.config.CertFile base.KeyFile = a.config.KeyFile base.ServerName = a.config.ServerName base.Domain = a.config.Domain base.TLSMinVersion = a.config.TLSMinVersion base.TLSCipherSuites = a.config.TLSCipherSuites base.TLSPreferServerCipherSuites = a.config.TLSPreferServerCipherSuites // Setup the user event callback base.UserEventHandler = func(e serf.UserEvent) { select { case a.eventCh <- e: case <-a.shutdownCh: } } // Setup the loggers base.LogOutput = a.LogOutput // This will set up the LAN keyring, as well as the WAN for servers. if err := a.setupKeyrings(base); err != nil { return nil, fmt.Errorf("Failed to configure keyring: %v", err) } return base, nil } // parseSingleIPTemplate is used as a helper function to parse out a single IP // address from a config parameter. func parseSingleIPTemplate(ipTmpl string) (string, error) { out, err := template.Parse(ipTmpl) if err != nil { return "", fmt.Errorf("Unable to parse address template %q: %v", ipTmpl, err) } ips := strings.Split(out, " ") switch len(ips) { case 0: return "", errors.New("No addresses found, please configure one.") case 1: return ips[0], nil default: return "", fmt.Errorf("Multiple addresses found (%q), please configure one.", out) } } // resolveTmplAddrs iterates over the myriad of addresses in the agent's config // and performs go-sockaddr/template Parse on each known address in case the // user specified a template config for any of their values. func (a *Agent) resolveTmplAddrs() error { if a.config.AdvertiseAddr != "" { ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddr) if err != nil { return fmt.Errorf("Advertise address resolution failed: %v", err) } a.config.AdvertiseAddr = ipStr } if a.config.Addresses.DNS != "" { ipStr, err := parseSingleIPTemplate(a.config.Addresses.DNS) if err != nil { return fmt.Errorf("DNS address resolution failed: %v", err) } a.config.Addresses.DNS = ipStr } if a.config.Addresses.HTTP != "" { ipStr, err := parseSingleIPTemplate(a.config.Addresses.HTTP) if err != nil { return fmt.Errorf("HTTP address resolution failed: %v", err) } a.config.Addresses.HTTP = ipStr } if a.config.Addresses.HTTPS != "" { ipStr, err := parseSingleIPTemplate(a.config.Addresses.HTTPS) if err != nil { return fmt.Errorf("HTTPS address resolution failed: %v", err) } a.config.Addresses.HTTPS = ipStr } if a.config.AdvertiseAddrWan != "" { ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddrWan) if err != nil { return fmt.Errorf("Advertise WAN address resolution failed: %v", err) } a.config.AdvertiseAddrWan = ipStr } if a.config.BindAddr != "" { ipStr, err := parseSingleIPTemplate(a.config.BindAddr) if err != nil { return fmt.Errorf("Bind address resolution failed: %v", err) } a.config.BindAddr = ipStr } if a.config.ClientAddr != "" { ipStr, err := parseSingleIPTemplate(a.config.ClientAddr) if err != nil { return fmt.Errorf("Client address resolution failed: %v", err) } a.config.ClientAddr = ipStr } if a.config.SerfLanBindAddr != "" { ipStr, err := parseSingleIPTemplate(a.config.SerfLanBindAddr) if err != nil { return fmt.Errorf("Serf LAN Address resolution failed: %v", err) } a.config.SerfLanBindAddr = ipStr } if a.config.SerfWanBindAddr != "" { ipStr, err := parseSingleIPTemplate(a.config.SerfWanBindAddr) if err != nil { return fmt.Errorf("Serf WAN Address resolution failed: %v", err) } a.config.SerfWanBindAddr = ipStr } // Parse all tagged addresses for k, v := range a.config.TaggedAddresses { ipStr, err := parseSingleIPTemplate(v) if err != nil { return fmt.Errorf("%s address resolution failed: %v", k, err) } a.config.TaggedAddresses[k] = ipStr } return nil } // makeRandomID will generate a random UUID for a node. func (a *Agent) makeRandomID() (string, error) { id, err := uuid.GenerateUUID() if err != nil { return "", err } a.logger.Printf("[DEBUG] Using random ID %q as node ID", id) return id, nil } // makeNodeID will try to find a host-specific ID, or else will generate a // random ID. The returned ID will always be formatted as a GUID. We don't tell // the caller whether this ID is random or stable since the consequences are // high for us if this changes, so we will persist it either way. This will let // gopsutil change implementations without affecting in-place upgrades of nodes. func (a *Agent) makeNodeID() (string, error) { // If they've disabled host-based IDs then just make a random one. if *a.config.DisableHostNodeID { return a.makeRandomID() } // Try to get a stable ID associated with the host itself. info, err := host.Info() if err != nil { a.logger.Printf("[DEBUG] Couldn't get a unique ID from the host: %v", err) return a.makeRandomID() } // Make sure the host ID parses as a UUID, since we don't have complete // control over this process. id := strings.ToLower(info.HostID) if _, err := uuid.ParseUUID(id); err != nil { a.logger.Printf("[DEBUG] Unique ID %q from host isn't formatted as a UUID: %v", id, err) return a.makeRandomID() } // Hash the input to make it well distributed. The reported Host UUID may be // similar across nodes if they are on a cloud provider or on motherboards // created from the same batch. buf := sha512.Sum512([]byte(id)) id = fmt.Sprintf("%08x-%04x-%04x-%04x-%12x", buf[0:4], buf[4:6], buf[6:8], buf[8:10], buf[10:16]) a.logger.Printf("[DEBUG] Using unique ID %q from host as node ID", id) return id, nil } // setupNodeID will pull the persisted node ID, if any, or create a random one // and persist it. func (a *Agent) setupNodeID(config *Config) error { // If they've configured a node ID manually then just use that, as // long as it's valid. if config.NodeID != "" { config.NodeID = types.NodeID(strings.ToLower(string(config.NodeID))) if _, err := uuid.ParseUUID(string(config.NodeID)); err != nil { return err } return nil } // For dev mode we have no filesystem access so just make one. if a.config.DevMode { id, err := a.makeNodeID() if err != nil { return err } config.NodeID = types.NodeID(id) return nil } // Load saved state, if any. Since a user could edit this, we also // validate it. fileID := filepath.Join(config.DataDir, "node-id") if _, err := os.Stat(fileID); err == nil { rawID, err := ioutil.ReadFile(fileID) if err != nil { return err } nodeID := strings.TrimSpace(string(rawID)) nodeID = strings.ToLower(nodeID) if _, err := uuid.ParseUUID(nodeID); err != nil { return err } config.NodeID = types.NodeID(nodeID) } // If we still don't have a valid node ID, make one. if config.NodeID == "" { id, err := a.makeNodeID() if err != nil { return err } if err := lib.EnsurePath(fileID, false); err != nil { return err } if err := ioutil.WriteFile(fileID, []byte(id), 0600); err != nil { return err } config.NodeID = types.NodeID(id) } return nil } // setupKeyrings is used to initialize and load keyrings during agent startup func (a *Agent) setupKeyrings(config *consul.Config) error { // If the keyring file is disabled then just poke the provided key // into the in-memory keyring. if a.config.DisableKeyringFile { if a.config.EncryptKey == "" { return nil } keys := []string{a.config.EncryptKey} if err := loadKeyring(config.SerfLANConfig, keys); err != nil { return err } if a.config.Server { if err := loadKeyring(config.SerfWANConfig, keys); err != nil { return err } } return nil } // Otherwise, we need to deal with the keyring files. fileLAN := filepath.Join(a.config.DataDir, SerfLANKeyring) fileWAN := filepath.Join(a.config.DataDir, SerfWANKeyring) if a.config.EncryptKey == "" { goto LOAD } if _, err := os.Stat(fileLAN); err != nil { if err := initKeyring(fileLAN, a.config.EncryptKey); err != nil { return err } } if a.config.Server { if _, err := os.Stat(fileWAN); err != nil { if err := initKeyring(fileWAN, a.config.EncryptKey); err != nil { return err } } } LOAD: if _, err := os.Stat(fileLAN); err == nil { config.SerfLANConfig.KeyringFile = fileLAN } if err := loadKeyringFile(config.SerfLANConfig); err != nil { return err } if a.config.Server { if _, err := os.Stat(fileWAN); err == nil { config.SerfWANConfig.KeyringFile = fileWAN } if err := loadKeyringFile(config.SerfWANConfig); err != nil { return err } } return nil } // registerEndpoint registers a handler for the consul RPC server // under a unique name while making it accessible under the provided // name. This allows overwriting handlers for the golang net/rpc // service which does not allow this. func (a *Agent) registerEndpoint(name string, handler interface{}) error { srv, ok := a.delegate.(*consul.Server) if !ok { panic("agent must be a server") } realname := fmt.Sprintf("%s-%d", name, time.Now().UnixNano()) a.endpointsLock.Lock() a.endpoints[name] = realname a.endpointsLock.Unlock() return srv.RegisterEndpoint(realname, handler) } // RPC is used to make an RPC call to the Consul servers // This allows the agent to implement the Consul.Interface func (a *Agent) RPC(method string, args interface{}, reply interface{}) error { a.endpointsLock.Lock() // fast path: only translate if there are overrides if len(a.endpoints) > 0 { p := strings.SplitN(method, ".", 2) if e := a.endpoints[p[0]]; e != "" { method = e + "." + p[1] } } a.endpointsLock.Unlock() return a.delegate.RPC(method, args, reply) } // SnapshotRPC performs the requested snapshot RPC against the Consul server in // a streaming manner. The contents of in will be read and passed along as the // payload, and the response message will determine the error status, and any // return payload will be written to out. func (a *Agent) SnapshotRPC(args *structs.SnapshotRequest, in io.Reader, out io.Writer, replyFn structs.SnapshotReplyFn) error { return a.delegate.SnapshotRPC(args, in, out, replyFn) } // Leave is used to prepare the agent for a graceful shutdown func (a *Agent) Leave() error { return a.delegate.Leave() } // ShutdownAgent is used to hard stop the agent. Should be preceded by // Leave to do it gracefully. Should be followed by ShutdownEndpoints to // terminate the HTTP and DNS servers as well. func (a *Agent) ShutdownAgent() error { a.shutdownLock.Lock() defer a.shutdownLock.Unlock() if a.shutdown { return nil } a.logger.Println("[INFO] agent: Requesting shutdown") // Stop all the checks a.checkLock.Lock() defer a.checkLock.Unlock() for _, chk := range a.checkMonitors { chk.Stop() } for _, chk := range a.checkTTLs { chk.Stop() } for _, chk := range a.checkHTTPs { chk.Stop() } for _, chk := range a.checkTCPs { chk.Stop() } for _, chk := range a.checkDockers { chk.Stop() } var err error if a.delegate != nil { err = a.delegate.Shutdown() if _, ok := a.delegate.(*consul.Server); ok { a.logger.Print("[INFO] agent: consul server down") } else { a.logger.Print("[INFO] agent: consul client down") } } pidErr := a.deletePid() if pidErr != nil { a.logger.Println("[WARN] agent: could not delete pid file ", pidErr) } a.logger.Println("[INFO] agent: shutdown complete") a.shutdown = true close(a.shutdownCh) return err } // ShutdownEndpoints terminates the HTTP and DNS servers. Should be // preceeded by ShutdownAgent. func (a *Agent) ShutdownEndpoints() { a.shutdownLock.Lock() defer a.shutdownLock.Unlock() if len(a.dnsServers) == 0 || len(a.httpServers) == 0 { return } for _, srv := range a.dnsServers { a.logger.Printf("[INFO] agent: Stopping DNS server %s (%s)", srv.Server.Addr, srv.Server.Net) srv.Shutdown() } a.dnsServers = nil for _, srv := range a.httpServers { a.logger.Printf("[INFO] agent: Stopping %s server %s", strings.ToUpper(srv.proto), srv.Addr) ctx, cancel := context.WithTimeout(context.Background(), time.Second) defer cancel() srv.Shutdown(ctx) if ctx.Err() == context.DeadlineExceeded { a.logger.Printf("[WARN] agent: Timeout stopping %s server %s", strings.ToUpper(srv.proto), srv.Addr) } } a.httpServers = nil a.logger.Println("[INFO] agent: Waiting for endpoints to shut down") a.wgServers.Wait() a.logger.Print("[INFO] agent: Endpoints down") } // ReloadCh is used to return a channel that can be // used for triggering reloads and returning a response. func (a *Agent) ReloadCh() chan chan error { return a.reloadCh } // RetryJoinCh is a channel that transports errors // from the retry join process. func (a *Agent) RetryJoinCh() <-chan error { return a.retryJoinCh } // ShutdownCh is used to return a channel that can be // selected to wait for the agent to perform a shutdown. func (a *Agent) ShutdownCh() <-chan struct{} { return a.shutdownCh } // JoinLAN is used to have the agent join a LAN cluster func (a *Agent) JoinLAN(addrs []string) (n int, err error) { a.logger.Printf("[INFO] agent: (LAN) joining: %v", addrs) n, err = a.delegate.JoinLAN(addrs) a.logger.Printf("[INFO] agent: (LAN) joined: %d Err: %v", n, err) if err == nil && a.joinLANNotifier != nil { if notifErr := a.joinLANNotifier.Notify(systemd.Ready); notifErr != nil { a.logger.Printf("[DEBUG] agent: systemd notify failed: %v", notifErr) } } return } // JoinWAN is used to have the agent join a WAN cluster func (a *Agent) JoinWAN(addrs []string) (n int, err error) { a.logger.Printf("[INFO] agent: (WAN) joining: %v", addrs) if srv, ok := a.delegate.(*consul.Server); ok { n, err = srv.JoinWAN(addrs) } else { err = fmt.Errorf("Must be a server to join WAN cluster") } a.logger.Printf("[INFO] agent: (WAN) joined: %d Err: %v", n, err) return } // ForceLeave is used to remove a failed node from the cluster func (a *Agent) ForceLeave(node string) (err error) { a.logger.Printf("[INFO] Force leaving node: %v", node) err = a.delegate.RemoveFailedNode(node) if err != nil { a.logger.Printf("[WARN] Failed to remove node: %v", err) } return err } // LocalMember is used to return the local node func (a *Agent) LocalMember() serf.Member { return a.delegate.LocalMember() } // LANMembers is used to retrieve the LAN members func (a *Agent) LANMembers() []serf.Member { return a.delegate.LANMembers() } // WANMembers is used to retrieve the WAN members func (a *Agent) WANMembers() []serf.Member { if srv, ok := a.delegate.(*consul.Server); ok { return srv.WANMembers() } return nil } // StartSync is called once Services and Checks are registered. // This is called to prevent a race between clients and the anti-entropy routines func (a *Agent) StartSync() { // Start the anti entropy routine go a.state.antiEntropy(a.shutdownCh) } // PauseSync is used to pause anti-entropy while bulk changes are make func (a *Agent) PauseSync() { a.state.Pause() } // ResumeSync is used to unpause anti-entropy after bulk changes are make func (a *Agent) ResumeSync() { a.state.Resume() } // GetLANCoordinate returns the coordinate of this node in the local pool (assumes coordinates // are enabled, so check that before calling). func (a *Agent) GetLANCoordinate() (*coordinate.Coordinate, error) { return a.delegate.GetLANCoordinate() } // sendCoordinate is a long-running loop that periodically sends our coordinate // to the server. Closing the agent's shutdownChannel will cause this to exit. func (a *Agent) sendCoordinate() { for { rate := a.config.SyncCoordinateRateTarget min := a.config.SyncCoordinateIntervalMin intv := lib.RateScaledInterval(rate, min, len(a.LANMembers())) intv = intv + lib.RandomStagger(intv) select { case <-time.After(intv): members := a.LANMembers() grok, err := consul.CanServersUnderstandProtocol(members, 3) if err != nil { a.logger.Printf("[ERR] agent: Failed to check servers: %s", err) continue } if !grok { a.logger.Printf("[DEBUG] agent: Skipping coordinate updates until servers are upgraded") continue } c, err := a.GetLANCoordinate() if err != nil { a.logger.Printf("[ERR] agent: Failed to get coordinate: %s", err) continue } req := structs.CoordinateUpdateRequest{ Datacenter: a.config.Datacenter, Node: a.config.NodeName, Coord: c, WriteRequest: structs.WriteRequest{Token: a.config.GetTokenForAgent()}, } var reply struct{} if err := a.RPC("Coordinate.Update", &req, &reply); err != nil { if strings.Contains(err.Error(), permissionDenied) { a.logger.Printf("[WARN] agent: Coordinate update blocked by ACLs") } else { a.logger.Printf("[ERR] agent: Coordinate update error: %v", err) } continue } case <-a.shutdownCh: return } } } // reapServicesInternal does a single pass, looking for services to reap. func (a *Agent) reapServicesInternal() { reaped := make(map[string]struct{}) for checkID, check := range a.state.CriticalChecks() { // There's nothing to do if there's no service. if check.Check.ServiceID == "" { continue } // There might be multiple checks for one service, so // we don't need to reap multiple times. serviceID := check.Check.ServiceID if _, ok := reaped[serviceID]; ok { continue } // See if there's a timeout. a.checkLock.Lock() timeout, ok := a.checkReapAfter[checkID] a.checkLock.Unlock() // Reap, if necessary. We keep track of which service // this is so that we won't try to remove it again. if ok && check.CriticalFor > timeout { reaped[serviceID] = struct{}{} a.RemoveService(serviceID, true) a.logger.Printf("[INFO] agent: Check %q for service %q has been critical for too long; deregistered service", checkID, serviceID) } } } // reapServices is a long running goroutine that looks for checks that have been // critical too long and dregisters their associated services. func (a *Agent) reapServices() { for { select { case <-time.After(a.config.CheckReapInterval): a.reapServicesInternal() case <-a.shutdownCh: return } } } // persistedService is used to wrap a service definition and bundle it // with an ACL token so we can restore both at a later agent start. type persistedService struct { Token string Service *structs.NodeService } // persistService saves a service definition to a JSON file in the data dir func (a *Agent) persistService(service *structs.NodeService) error { svcPath := filepath.Join(a.config.DataDir, servicesDir, stringHash(service.ID)) wrapped := persistedService{ Token: a.state.ServiceToken(service.ID), Service: service, } encoded, err := json.Marshal(wrapped) if err != nil { return err } return writeFileAtomic(svcPath, encoded) } // purgeService removes a persisted service definition file from the data dir func (a *Agent) purgeService(serviceID string) error { svcPath := filepath.Join(a.config.DataDir, servicesDir, stringHash(serviceID)) if _, err := os.Stat(svcPath); err == nil { return os.Remove(svcPath) } return nil } // persistCheck saves a check definition to the local agent's state directory func (a *Agent) persistCheck(check *structs.HealthCheck, chkType *structs.CheckType) error { checkPath := filepath.Join(a.config.DataDir, checksDir, checkIDHash(check.CheckID)) // Create the persisted check wrapped := persistedCheck{ Check: check, ChkType: chkType, Token: a.state.CheckToken(check.CheckID), } encoded, err := json.Marshal(wrapped) if err != nil { return err } return writeFileAtomic(checkPath, encoded) } // purgeCheck removes a persisted check definition file from the data dir func (a *Agent) purgeCheck(checkID types.CheckID) error { checkPath := filepath.Join(a.config.DataDir, checksDir, checkIDHash(checkID)) if _, err := os.Stat(checkPath); err == nil { return os.Remove(checkPath) } return nil } // writeFileAtomic writes the given contents to a temporary file in the same // directory, does an fsync and then renames the file to its real path func writeFileAtomic(path string, contents []byte) error { uuid, err := uuid.GenerateUUID() if err != nil { return err } tempPath := fmt.Sprintf("%s-%s.tmp", path, uuid) if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil { return err } fh, err := os.OpenFile(tempPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0600) if err != nil { return err } if _, err := fh.Write(contents); err != nil { fh.Close() os.Remove(tempPath) return err } if err := fh.Sync(); err != nil { fh.Close() os.Remove(tempPath) return err } if err := fh.Close(); err != nil { os.Remove(tempPath) return err } if err := os.Rename(tempPath, path); err != nil { os.Remove(tempPath) return err } return nil } // AddService is used to add a service entry. // This entry is persistent and the agent will make a best effort to // ensure it is registered func (a *Agent) AddService(service *structs.NodeService, chkTypes []*structs.CheckType, persist bool, token string) error { if service.Service == "" { return fmt.Errorf("Service name missing") } if service.ID == "" && service.Service != "" { service.ID = service.Service } for _, check := range chkTypes { if !check.Valid() { return fmt.Errorf("Check type is not valid") } } // Warn if the service name is incompatible with DNS if !dnsNameRe.MatchString(service.Service) { a.logger.Printf("[WARN] Service name %q will not be discoverable "+ "via DNS due to invalid characters. Valid characters include "+ "all alpha-numerics and dashes.", service.Service) } // Warn if any tags are incompatible with DNS for _, tag := range service.Tags { if !dnsNameRe.MatchString(tag) { a.logger.Printf("[DEBUG] Service tag %q will not be discoverable "+ "via DNS due to invalid characters. Valid characters include "+ "all alpha-numerics and dashes.", tag) } } // Pause the service syncs during modification a.PauseSync() defer a.ResumeSync() // Take a snapshot of the current state of checks (if any), and // restore them before resuming anti-entropy. snap := a.snapshotCheckState() defer a.restoreCheckState(snap) // Add the service a.state.AddService(service, token) // Persist the service to a file if persist && !a.config.DevMode { if err := a.persistService(service); err != nil { return err } } // Create an associated health check for i, chkType := range chkTypes { checkID := string(chkType.CheckID) if checkID == "" { checkID = fmt.Sprintf("service:%s", service.ID) if len(chkTypes) > 1 { checkID += fmt.Sprintf(":%d", i+1) } } name := chkType.Name if name == "" { name = fmt.Sprintf("Service '%s' check", service.Service) } check := &structs.HealthCheck{ Node: a.config.NodeName, CheckID: types.CheckID(checkID), Name: name, Status: api.HealthCritical, Notes: chkType.Notes, ServiceID: service.ID, ServiceName: service.Service, } if chkType.Status != "" { check.Status = chkType.Status } if err := a.AddCheck(check, chkType, persist, token); err != nil { return err } } return nil } // RemoveService is used to remove a service entry. // The agent will make a best effort to ensure it is deregistered func (a *Agent) RemoveService(serviceID string, persist bool) error { // Validate ServiceID if serviceID == "" { return fmt.Errorf("ServiceID missing") } // Remove service immediately if err := a.state.RemoveService(serviceID); err != nil { a.logger.Printf("[WARN] agent: Failed to deregister service %q: %s", serviceID, err) return nil } // Remove the service from the data dir if persist { if err := a.purgeService(serviceID); err != nil { return err } } // Deregister any associated health checks for checkID, health := range a.state.Checks() { if health.ServiceID != serviceID { continue } if err := a.RemoveCheck(checkID, persist); err != nil { return err } } log.Printf("[DEBUG] agent: removed service %q", serviceID) return nil } // AddCheck is used to add a health check to the agent. // This entry is persistent and the agent will make a best effort to // ensure it is registered. The Check may include a CheckType which // is used to automatically update the check status func (a *Agent) AddCheck(check *structs.HealthCheck, chkType *structs.CheckType, persist bool, token string) error { if check.CheckID == "" { return fmt.Errorf("CheckID missing") } if chkType != nil { if !chkType.Valid() { return fmt.Errorf("Check type is not valid") } if chkType.IsScript() && !a.config.EnableScriptChecks { return fmt.Errorf("Scripts are disabled on this agent; to enable, configure 'enable_script_checks' to true") } } if check.ServiceID != "" { svc, ok := a.state.Services()[check.ServiceID] if !ok { return fmt.Errorf("ServiceID %q does not exist", check.ServiceID) } check.ServiceName = svc.Service } a.checkLock.Lock() defer a.checkLock.Unlock() // Check if already registered if chkType != nil { switch { case chkType.IsTTL(): if existing, ok := a.checkTTLs[check.CheckID]; ok { existing.Stop() delete(a.checkTTLs, check.CheckID) } ttl := &CheckTTL{ Notify: a.state, CheckID: check.CheckID, TTL: chkType.TTL, Logger: a.logger, } // Restore persisted state, if any if err := a.loadCheckState(check); err != nil { a.logger.Printf("[WARN] agent: failed restoring state for check %q: %s", check.CheckID, err) } ttl.Start() a.checkTTLs[check.CheckID] = ttl case chkType.IsHTTP(): if existing, ok := a.checkHTTPs[check.CheckID]; ok { existing.Stop() delete(a.checkHTTPs, check.CheckID) } if chkType.Interval < MinInterval { a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v", check.CheckID, MinInterval)) chkType.Interval = MinInterval } http := &CheckHTTP{ Notify: a.state, CheckID: check.CheckID, HTTP: chkType.HTTP, Header: chkType.Header, Method: chkType.Method, Interval: chkType.Interval, Timeout: chkType.Timeout, Logger: a.logger, TLSSkipVerify: chkType.TLSSkipVerify, } http.Start() a.checkHTTPs[check.CheckID] = http case chkType.IsTCP(): if existing, ok := a.checkTCPs[check.CheckID]; ok { existing.Stop() delete(a.checkTCPs, check.CheckID) } if chkType.Interval < MinInterval { a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v", check.CheckID, MinInterval)) chkType.Interval = MinInterval } tcp := &CheckTCP{ Notify: a.state, CheckID: check.CheckID, TCP: chkType.TCP, Interval: chkType.Interval, Timeout: chkType.Timeout, Logger: a.logger, } tcp.Start() a.checkTCPs[check.CheckID] = tcp case chkType.IsDocker(): if existing, ok := a.checkDockers[check.CheckID]; ok { existing.Stop() delete(a.checkDockers, check.CheckID) } if chkType.Interval < MinInterval { a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v", check.CheckID, MinInterval)) chkType.Interval = MinInterval } if a.dockerClient == nil { dc, err := NewDockerClient(os.Getenv("DOCKER_HOST"), CheckBufSize) if err != nil { a.logger.Printf("[ERR] agent: error creating docker client: %s", err) return err } a.logger.Printf("[DEBUG] agent: created docker client for %s", dc.host) a.dockerClient = dc } dockerCheck := &CheckDocker{ Notify: a.state, CheckID: check.CheckID, DockerContainerID: chkType.DockerContainerID, Shell: chkType.Shell, Script: chkType.Script, Interval: chkType.Interval, Logger: a.logger, client: a.dockerClient, } dockerCheck.Start() a.checkDockers[check.CheckID] = dockerCheck case chkType.IsMonitor(): if existing, ok := a.checkMonitors[check.CheckID]; ok { existing.Stop() delete(a.checkMonitors, check.CheckID) } if chkType.Interval < MinInterval { a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v", check.CheckID, MinInterval)) chkType.Interval = MinInterval } monitor := &CheckMonitor{ Notify: a.state, CheckID: check.CheckID, Script: chkType.Script, Interval: chkType.Interval, Timeout: chkType.Timeout, Logger: a.logger, } monitor.Start() a.checkMonitors[check.CheckID] = monitor default: return fmt.Errorf("Check type is not valid") } if chkType.DeregisterCriticalServiceAfter > 0 { timeout := chkType.DeregisterCriticalServiceAfter if timeout < a.config.CheckDeregisterIntervalMin { timeout = a.config.CheckDeregisterIntervalMin a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has deregister interval below minimum of %v", check.CheckID, a.config.CheckDeregisterIntervalMin)) } a.checkReapAfter[check.CheckID] = timeout } else { delete(a.checkReapAfter, check.CheckID) } } // Add to the local state for anti-entropy err := a.state.AddCheck(check, token) if err != nil { a.cancelCheckMonitors(check.CheckID) return err } // Persist the check if persist && !a.config.DevMode { return a.persistCheck(check, chkType) } return nil } // RemoveCheck is used to remove a health check. // The agent will make a best effort to ensure it is deregistered func (a *Agent) RemoveCheck(checkID types.CheckID, persist bool) error { // Validate CheckID if checkID == "" { return fmt.Errorf("CheckID missing") } // Add to the local state for anti-entropy a.state.RemoveCheck(checkID) a.checkLock.Lock() defer a.checkLock.Unlock() a.cancelCheckMonitors(checkID) if persist { if err := a.purgeCheck(checkID); err != nil { return err } if err := a.purgeCheckState(checkID); err != nil { return err } } a.logger.Printf("[DEBUG] agent: removed check %q", checkID) return nil } func (a *Agent) cancelCheckMonitors(checkID types.CheckID) { // Stop any monitors delete(a.checkReapAfter, checkID) if check, ok := a.checkMonitors[checkID]; ok { check.Stop() delete(a.checkMonitors, checkID) } if check, ok := a.checkHTTPs[checkID]; ok { check.Stop() delete(a.checkHTTPs, checkID) } if check, ok := a.checkTCPs[checkID]; ok { check.Stop() delete(a.checkTCPs, checkID) } if check, ok := a.checkTTLs[checkID]; ok { check.Stop() delete(a.checkTTLs, checkID) } if check, ok := a.checkDockers[checkID]; ok { check.Stop() delete(a.checkDockers, checkID) } } // updateTTLCheck is used to update the status of a TTL check via the Agent API. func (a *Agent) updateTTLCheck(checkID types.CheckID, status, output string) error { a.checkLock.Lock() defer a.checkLock.Unlock() // Grab the TTL check. check, ok := a.checkTTLs[checkID] if !ok { return fmt.Errorf("CheckID %q does not have associated TTL", checkID) } // Set the status through CheckTTL to reset the TTL. check.SetStatus(status, output) // We don't write any files in dev mode so bail here. if a.config.DevMode { return nil } // Persist the state so the TTL check can come up in a good state after // an agent restart, especially with long TTL values. if err := a.persistCheckState(check, status, output); err != nil { return fmt.Errorf("failed persisting state for check %q: %s", checkID, err) } return nil } // persistCheckState is used to record the check status into the data dir. // This allows the state to be restored on a later agent start. Currently // only useful for TTL based checks. func (a *Agent) persistCheckState(check *CheckTTL, status, output string) error { // Create the persisted state state := persistedCheckState{ CheckID: check.CheckID, Status: status, Output: output, Expires: time.Now().Add(check.TTL).Unix(), } // Encode the state buf, err := json.Marshal(state) if err != nil { return err } // Create the state dir if it doesn't exist dir := filepath.Join(a.config.DataDir, checkStateDir) if err := os.MkdirAll(dir, 0700); err != nil { return fmt.Errorf("failed creating check state dir %q: %s", dir, err) } // Write the state to the file file := filepath.Join(dir, checkIDHash(check.CheckID)) // Create temp file in same dir, to make more likely atomic tempFile := file + ".tmp" // persistCheckState is called frequently, so don't use writeFileAtomic to avoid calling fsync here if err := ioutil.WriteFile(tempFile, buf, 0600); err != nil { return fmt.Errorf("failed writing temp file %q: %s", tempFile, err) } if err := os.Rename(tempFile, file); err != nil { return fmt.Errorf("failed to rename temp file from %q to %q: %s", tempFile, file, err) } return nil } // loadCheckState is used to restore the persisted state of a check. func (a *Agent) loadCheckState(check *structs.HealthCheck) error { // Try to read the persisted state for this check file := filepath.Join(a.config.DataDir, checkStateDir, checkIDHash(check.CheckID)) buf, err := ioutil.ReadFile(file) if err != nil { if os.IsNotExist(err) { return nil } return fmt.Errorf("failed reading file %q: %s", file, err) } // Decode the state data var p persistedCheckState if err := json.Unmarshal(buf, &p); err != nil { a.logger.Printf("[ERR] agent: failed decoding check state: %s", err) return a.purgeCheckState(check.CheckID) } // Check if the state has expired if time.Now().Unix() >= p.Expires { a.logger.Printf("[DEBUG] agent: check state expired for %q, not restoring", check.CheckID) return a.purgeCheckState(check.CheckID) } // Restore the fields from the state check.Output = p.Output check.Status = p.Status return nil } // purgeCheckState is used to purge the state of a check from the data dir func (a *Agent) purgeCheckState(checkID types.CheckID) error { file := filepath.Join(a.config.DataDir, checkStateDir, checkIDHash(checkID)) err := os.Remove(file) if os.IsNotExist(err) { return nil } return err } func (a *Agent) GossipEncrypted() bool { return a.delegate.Encrypted() } // Stats is used to get various debugging state from the sub-systems func (a *Agent) Stats() map[string]map[string]string { toString := func(v uint64) string { return strconv.FormatUint(v, 10) } stats := a.delegate.Stats() stats["agent"] = map[string]string{ "check_monitors": toString(uint64(len(a.checkMonitors))), "check_ttls": toString(uint64(len(a.checkTTLs))), "checks": toString(uint64(len(a.state.checks))), "services": toString(uint64(len(a.state.services))), } revision := a.config.Revision if len(revision) > 8 { revision = revision[:8] } stats["build"] = map[string]string{ "revision": revision, "version": a.config.Version, "prerelease": a.config.VersionPrerelease, } return stats } // storePid is used to write out our PID to a file if necessary func (a *Agent) storePid() error { // Quit fast if no pidfile pidPath := a.config.PidFile if pidPath == "" { return nil } // Open the PID file pidFile, err := os.OpenFile(pidPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0666) if err != nil { return fmt.Errorf("Could not open pid file: %v", err) } defer pidFile.Close() // Write out the PID pid := os.Getpid() _, err = pidFile.WriteString(fmt.Sprintf("%d", pid)) if err != nil { return fmt.Errorf("Could not write to pid file: %s", err) } return nil } // deletePid is used to delete our PID on exit func (a *Agent) deletePid() error { // Quit fast if no pidfile pidPath := a.config.PidFile if pidPath == "" { return nil } stat, err := os.Stat(pidPath) if err != nil { return fmt.Errorf("Could not remove pid file: %s", err) } if stat.IsDir() { return fmt.Errorf("Specified pid file path is directory") } err = os.Remove(pidPath) if err != nil { return fmt.Errorf("Could not remove pid file: %s", err) } return nil } // loadServices will load service definitions from configuration and persisted // definitions on disk, and load them into the local agent. func (a *Agent) loadServices(conf *Config) error { // Register the services from config for _, service := range conf.Services { ns := service.NodeService() chkTypes := service.CheckTypes() if err := a.AddService(ns, chkTypes, false, service.Token); err != nil { return fmt.Errorf("Failed to register service '%s': %v", service.ID, err) } } // Load any persisted services svcDir := filepath.Join(a.config.DataDir, servicesDir) files, err := ioutil.ReadDir(svcDir) if err != nil { if os.IsNotExist(err) { return nil } return fmt.Errorf("Failed reading services dir %q: %s", svcDir, err) } for _, fi := range files { // Skip all dirs if fi.IsDir() { continue } // Skip all partially written temporary files if strings.HasSuffix(fi.Name(), "tmp") { a.logger.Printf("[WARN] Ignoring temporary service file %v", fi.Name()) continue } // Open the file for reading file := filepath.Join(svcDir, fi.Name()) fh, err := os.Open(file) if err != nil { return fmt.Errorf("failed opening service file %q: %s", file, err) } // Read the contents into a buffer buf, err := ioutil.ReadAll(fh) fh.Close() if err != nil { return fmt.Errorf("failed reading service file %q: %s", file, err) } // Try decoding the service definition var p persistedService if err := json.Unmarshal(buf, &p); err != nil { // Backwards-compatibility for pre-0.5.1 persisted services if err := json.Unmarshal(buf, &p.Service); err != nil { return fmt.Errorf("failed decoding service file %q: %s", file, err) } } serviceID := p.Service.ID if _, ok := a.state.services[serviceID]; ok { // Purge previously persisted service. This allows config to be // preferred over services persisted from the API. a.logger.Printf("[DEBUG] agent: service %q exists, not restoring from %q", serviceID, file) if err := a.purgeService(serviceID); err != nil { return fmt.Errorf("failed purging service %q: %s", serviceID, err) } } else { a.logger.Printf("[DEBUG] agent: restored service definition %q from %q", serviceID, file) if err := a.AddService(p.Service, nil, false, p.Token); err != nil { return fmt.Errorf("failed adding service %q: %s", serviceID, err) } } } return nil } // unloadServices will deregister all services other than the 'consul' service // known to the local agent. func (a *Agent) unloadServices() error { for _, service := range a.state.Services() { if err := a.RemoveService(service.ID, false); err != nil { return fmt.Errorf("Failed deregistering service '%s': %v", service.ID, err) } } return nil } // loadChecks loads check definitions and/or persisted check definitions from // disk and re-registers them with the local agent. func (a *Agent) loadChecks(conf *Config) error { // Register the checks from config for _, check := range conf.Checks { health := check.HealthCheck(conf.NodeName) chkType := check.CheckType() if err := a.AddCheck(health, chkType, false, check.Token); err != nil { return fmt.Errorf("Failed to register check '%s': %v %v", check.Name, err, check) } } // Load any persisted checks checkDir := filepath.Join(a.config.DataDir, checksDir) files, err := ioutil.ReadDir(checkDir) if err != nil { if os.IsNotExist(err) { return nil } return fmt.Errorf("Failed reading checks dir %q: %s", checkDir, err) } for _, fi := range files { // Ignore dirs - we only care about the check definition files if fi.IsDir() { continue } // Open the file for reading file := filepath.Join(checkDir, fi.Name()) fh, err := os.Open(file) if err != nil { return fmt.Errorf("Failed opening check file %q: %s", file, err) } // Read the contents into a buffer buf, err := ioutil.ReadAll(fh) fh.Close() if err != nil { return fmt.Errorf("failed reading check file %q: %s", file, err) } // Decode the check var p persistedCheck if err := json.Unmarshal(buf, &p); err != nil { return fmt.Errorf("Failed decoding check file %q: %s", file, err) } checkID := p.Check.CheckID if _, ok := a.state.checks[checkID]; ok { // Purge previously persisted check. This allows config to be // preferred over persisted checks from the API. a.logger.Printf("[DEBUG] agent: check %q exists, not restoring from %q", checkID, file) if err := a.purgeCheck(checkID); err != nil { return fmt.Errorf("Failed purging check %q: %s", checkID, err) } } else { // Default check to critical to avoid placing potentially unhealthy // services into the active pool p.Check.Status = api.HealthCritical if err := a.AddCheck(p.Check, p.ChkType, false, p.Token); err != nil { // Purge the check if it is unable to be restored. a.logger.Printf("[WARN] agent: Failed to restore check %q: %s", checkID, err) if err := a.purgeCheck(checkID); err != nil { return fmt.Errorf("Failed purging check %q: %s", checkID, err) } } a.logger.Printf("[DEBUG] agent: restored health check %q from %q", p.Check.CheckID, file) } } return nil } // unloadChecks will deregister all checks known to the local agent. func (a *Agent) unloadChecks() error { for _, check := range a.state.Checks() { if err := a.RemoveCheck(check.CheckID, false); err != nil { return fmt.Errorf("Failed deregistering check '%s': %s", check.CheckID, err) } } return nil } // snapshotCheckState is used to snapshot the current state of the health // checks. This is done before we reload our checks, so that we can properly // restore into the same state. func (a *Agent) snapshotCheckState() map[types.CheckID]*structs.HealthCheck { return a.state.Checks() } // restoreCheckState is used to reset the health state based on a snapshot. // This is done after we finish the reload to avoid any unnecessary flaps // in health state and potential session invalidations. func (a *Agent) restoreCheckState(snap map[types.CheckID]*structs.HealthCheck) { for id, check := range snap { a.state.UpdateCheck(id, check.Status, check.Output) } } // loadMetadata loads node metadata fields from the agent config and // updates them on the local agent. func (a *Agent) loadMetadata(conf *Config) error { a.state.Lock() defer a.state.Unlock() for key, value := range conf.Meta { a.state.metadata[key] = value } a.state.changeMade() return nil } // unloadMetadata resets the local metadata state func (a *Agent) unloadMetadata() { a.state.Lock() defer a.state.Unlock() a.state.metadata = make(map[string]string) } // serviceMaintCheckID returns the ID of a given service's maintenance check func serviceMaintCheckID(serviceID string) types.CheckID { return types.CheckID(structs.ServiceMaintPrefix + serviceID) } // EnableServiceMaintenance will register a false health check against the given // service ID with critical status. This will exclude the service from queries. func (a *Agent) EnableServiceMaintenance(serviceID, reason, token string) error { service, ok := a.state.Services()[serviceID] if !ok { return fmt.Errorf("No service registered with ID %q", serviceID) } // Check if maintenance mode is not already enabled checkID := serviceMaintCheckID(serviceID) if _, ok := a.state.Checks()[checkID]; ok { return nil } // Use default notes if no reason provided if reason == "" { reason = defaultServiceMaintReason } // Create and register the critical health check check := &structs.HealthCheck{ Node: a.config.NodeName, CheckID: checkID, Name: "Service Maintenance Mode", Notes: reason, ServiceID: service.ID, ServiceName: service.Service, Status: api.HealthCritical, } a.AddCheck(check, nil, true, token) a.logger.Printf("[INFO] agent: Service %q entered maintenance mode", serviceID) return nil } // DisableServiceMaintenance will deregister the fake maintenance mode check // if the service has been marked as in maintenance. func (a *Agent) DisableServiceMaintenance(serviceID string) error { if _, ok := a.state.Services()[serviceID]; !ok { return fmt.Errorf("No service registered with ID %q", serviceID) } // Check if maintenance mode is enabled checkID := serviceMaintCheckID(serviceID) if _, ok := a.state.Checks()[checkID]; !ok { return nil } // Deregister the maintenance check a.RemoveCheck(checkID, true) a.logger.Printf("[INFO] agent: Service %q left maintenance mode", serviceID) return nil } // EnableNodeMaintenance places a node into maintenance mode. func (a *Agent) EnableNodeMaintenance(reason, token string) { // Ensure node maintenance is not already enabled if _, ok := a.state.Checks()[structs.NodeMaint]; ok { return } // Use a default notes value if reason == "" { reason = defaultNodeMaintReason } // Create and register the node maintenance check check := &structs.HealthCheck{ Node: a.config.NodeName, CheckID: structs.NodeMaint, Name: "Node Maintenance Mode", Notes: reason, Status: api.HealthCritical, } a.AddCheck(check, nil, true, token) a.logger.Printf("[INFO] agent: Node entered maintenance mode") } // DisableNodeMaintenance removes a node from maintenance mode func (a *Agent) DisableNodeMaintenance() { if _, ok := a.state.Checks()[structs.NodeMaint]; !ok { return } a.RemoveCheck(structs.NodeMaint, true) a.logger.Printf("[INFO] agent: Node left maintenance mode") } func (a *Agent) ReloadConfig(newCfg *Config) error { // Bulk update the services and checks a.PauseSync() defer a.ResumeSync() // Snapshot the current state, and restore it afterwards snap := a.snapshotCheckState() defer a.restoreCheckState(snap) // First unload all checks, services, and metadata. This lets us begin the reload // with a clean slate. if err := a.unloadServices(); err != nil { return fmt.Errorf("Failed unloading services: %s", err) } if err := a.unloadChecks(); err != nil { return fmt.Errorf("Failed unloading checks: %s", err) } a.unloadMetadata() // Reload service/check definitions and metadata. if err := a.loadServices(newCfg); err != nil { return fmt.Errorf("Failed reloading services: %s", err) } if err := a.loadChecks(newCfg); err != nil { return fmt.Errorf("Failed reloading checks: %s", err) } if err := a.loadMetadata(newCfg); err != nil { return fmt.Errorf("Failed reloading metadata: %s", err) } if err := a.reloadWatches(newCfg); err != nil { return fmt.Errorf("Failed reloading watches: %v", err) } return nil }